It is well known that clarification process is one of the most important processes in sugar production process since it determines how good the quality of the product. But, it also important to note that this process contributes a big share of sugar losses in the process. Thus, the process of precipitation in clarifier is a vulnerable time. Because the juice is stored at high temperatures in a relatively long time. If the previous process (defecation-adding slaked lime and sulphitation) was not perfect, we can be sure that there will be several serious problems, such as loss of sugar due to inversion, sugar damage due to high temperature and the formation of colored materials that have a big effect on the quality of sugar products. So, it is strongly recommended that the control of the defecation and sulphitation process be done automatically so that the constraints that harm the process can be minimized.
Most of the old sugar factories are still in manual operation where most of its parameter is still measured in batch and done manually. The quality control is usually done hourly, leaving the process uncontrolled during the sampling time. Although the equipment to measure the quality parameter is already sophisticated, performing the measurement in wide interval time may open opportunity to process deviation. As suggested above, automation can help to have smooth process control. Furthermore, any deviation occurred can be monitored easily. Also, the operator and engineer can create data trend to predict problems and to support root cause analysis.
Several parameters that need to be monitored continuously during defecation and sulphitation process are the temperature of juice, pH, the flow rate of juice, the flow rate of slaked lime, the flow rate of Sulphur dioxide, the concentration of juice, concentration of slaked lime, and flocculant dosing/concentration. Currently, online and in-line measuring devices are available, thus enabling the above parameter to be measured continuously.